1. Field of the Invention
The present invention relates to conduits for the delivery of gases, and in particular to conduits for the delivery of gases to patients in a medical environment.
2. Summary of the Prior Art
Many methods are known in the art for supplying humidified gases to a patient requiring breathing assistance. It is known in the art to provide a heater to minimise condensation on the internal surfaces of the conduit. In that regard it is known to provide a plain or coiled heater wire within the lumen of the conduit, such an embodiment being illustrated in for example U.S. Pat. No. 6,078,730. In this case the heater wire is disposed within the gases flow and maintain the temperature of the gases flow to reduce condensation. It is also known to provide a heater wire on the conduit, for example disposed helically on the outer wall of the conduit as in U.S. Pat. No. 5,454,061. This heats the conduit wall, to in turn heat the gases flowing through the lumen of the conduit.
While these heated wall conduits are reasonably effective there is still room for improvement. Furthermore, the forming method involves winding the conduit from a thin narrow tape applied to a mandrel with adjacent turns overlapping. This forming method is comparatively slow, making these conduits expensive to manufacture.